Magnetic system for separation of iron from refuse

ABSTRACT

A plurality of spaced conveyors containing stationary magnets are sequentially arranged to remove ferromagnetic particles from a mixture of said particle and refuse that are initially transported to a position below the first conveyor containing a magnet in its lower run. A blower directs air blasts along the path of transport to assist in the separation.

United States Patent 1 Riisner 1 1 MAGNETIC SYSTEM FOR SEPARATION OF IRON FROM REFUSE [75] Inventor: Kurt Riisner, Mu nsteflwesb Y phalia, Germany [73] Assignees iiii'ima giiitzeriiiEini-hlig-Uird' Zement-Maschinenbau-Gesellschaft m.b.H.

[22] Filed: Sept. 29, 1970 [21] Appl. No.: 76,362

[30] Foreign Application Priority Data Nov. 17, 1969 Gennany P 19 57 636.4

[52] US. Cl 209/39, 209/216, 209/223 [51] Int. Cl. 1303c l/30 [58] Field of Search 209/214, 216, 218, 209/223 R, 223 A, 318, 11, 39

[56] References Cited UNITED STATES PATENTS 422,732 3/1890 Conkling 209/223 R 434,588 8/1890 Edison 209/39 548,176 10/1895 Buchanan.... 209/216 673,172 4/1901 McKnight 209/218 [451 Sept. 4, 1973 971,163 9/1910 Wood 209/223 A 1,360,062 11/1920 Waitekaites 209/318 X 2,604,207 7/1952 Scott i 209/39 X 2,699,867 1/1955 Kitten 209/318 X 3,384,232 3/1968 Tumbull 209/11 3,497,061 2/1970 Ferris 209/223 R 2,826,302 3/1958 Scott 209/218 FOREIGN PATENTS OR APPLICATIONS 450,773 8/1949 Italy 209/223 465,406 9/1951 Italy 209/218 OTHER PUBLICATIONS Sci. American (Edison), Vol. XLIII, 1880, pg. 36.

Primary Examiner-Robert I-lalper Attorney-Michael S. Striker [57] ABSTRACT A plurality of spaced conveyors containing stationary magnets are sequentially arranged to remove ferromagnetic particles from a mixture of said particle and refuse that are initially transported to a position below the first conveyor containing a magnet in its lower run. A blower directs air blasts along the path of transport to assist in the separation.

5 Claims, 1 Drawing Figure MAGNETIC SYSTEM FOR SEPARATION OF IRON FROM REFUSE BACKGROUND OF THE INVENTION The separation of metallic iron from refuse is desired because of the value of the metallic iron and also because of the fact that the iron can damage machinery used in the subsequent processing of the refuse. The use of magnets to remove the iron fraction of refuse is well known, where the magnets are installed in the drums of a conveyor belt or positioned behind the conveyor belt. However, due to the extraordinarily variable nature of the refuse, it is inevitable that the iron separated from the refuse will be matted with other portions of the refuse. The value of the scrap thus obtained is seriously decreased as a result of the presence of the contaminants.

It has been attempted to affect a further degree of separation of the metallic iron from its contaminants by use of a second stage of magnetic sorting. Such a process has not been completely successful because the iron particles are relatively stationary and are in a stacked arrangement on the magnet whereby the noniron particles cling to the surface of the iron as a result of which they are carried along with the iron particles.

SUMMARY OF THE INVENTION In the apparatus according to the present invention, the mixture of iron particles and non-iron particles is presented to a magnetic field in such a way that the iron particles are drawn into it, weereas the non-iron particles are presented with the possibility of separating from the iron particles and falling away. This step is affected by permitting the contaminated iron falling from a first magnetic belt to fall past a second magnetic belt rising almost vertically. The iron components are collected on the belt and the remaining refuse components fall away from the iron under the influence of their own weight.

In a further embodiment of the invention, the separation of the iron components from the non-iron components can be facilitated by the use of a directed stream of air. A second stage of separation by means of an air stream can be arranged; this is effected by the use of the nearly-vertical magnetic conveyor belt to transport the partially-cleaned iron to a collection point. At this point the iron falls off the belt and can be subjected to a transverse air stream to remove the remaining contaminants.

The novel features whichare considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The drawing shows the magnetic conveyor belt and the air blowers used to effect the separation between iron and non-magnetic components in refuse.

DESCRIPTION OF I THE PREFERRED EMBODIMENTS Refuse containing iron components is brought into the system by the conventional conveyor 1. The belt of conveyor 1 passes underneath a second conveyor in which a magnet 2 is positioned above the belt 3. Iron is drawn from the refuse to the belt 3 which then carries it to the region 4 which is beyond the field of the magnet. The mixture falls away from the belt in a parabolic path and into the field of the magnets 5 positioned behind the belt of a nearly-vertically rising conveyor. The sharp acceleration of the iron particles as they come within the field of the magnets 5 tends to throw loose the contaminants. This process is facilitated by means of the air stream provided by the blower 7. The nonmagnetic particles fall onto the conveyor 6 which removes them from the system.

The conveyor associated with the magnet 5 carries the now-nearly clean iron particles to a higher level from which the iron particles fall through a shaft 9 into a container 10. During the fall through the shaft 9, the particles are once more subjected to the effect of an air stream llll supplied by a second blower. The air stream, which is essentially horizontal in direction, tends to remove any last traces of contaminants still clinging to the iron particles. Such traces as are removed are carried through a shaft 12 by gravity and fall to the conveyor 6 which removes the particles from the system. The air stream in the shaft 12 is vented through the louvres 13.

The special advantage of the present process lies in the fact that the separation between the iron and noniron components is essentially complete, as a result of which the value of the iron scrap thus obtained in substantially increased.

It is, of course, recognized that the process described herein actually separates ferromagnetic from non-ferromagnetic materials. However, ferromagnetic materials other than iron are relatively rarely encountered in refuse, so the iron has been considered herein as though it were the only ferromagnetic material. Nevertheless, the presence of other ferromagnetic materials would be undesirable in refuse to be further treated, and the process described would separate such materials from the refuse.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and described to be protected by Letters Patent is set forth in the appended claims:

1. Apparatus for separating ferromagnetic particles from a mixture of said ferromagnetic particles and non-ferromagnetic particles comprising a first conveyor for transporting the mixture in a first direction;-

a belt conveyor having a lower run upwardly spaced from said first conveyor and extending in a direction transverse to said first direction with one end of said lower run transversely spaced from said first conveyor; a magnet arranged over said first conveyor spaced from said one end of said lower run and closely adjacent to that face of said lower run of said belt conveyor which faces away from said first conveyor so that the ferromagnetic particles and some of the non-ferromagnetic particles clinging thereto will be lifted by said magnet onto said lower run and transported on the latter in said transverse direction out of the influence of the magnetic field of said magnet so that the lifted particles will fall freely along a curved path from said one end of said lower run; a further belt conveyor having an upwardly moving run spaced from said magnetic field and said curved path; and magnet means located closely adjacent that face of said upwardly moving run which faces away from said curved path so that the ferromagnetic particles will be attracted by said magnet means while falling along said curved path and be deflected out of said curved path against said upwardly moving run to be transported by the latter and separated from the remaining non-ferromagnetic particles which will not be attracted but continue to drop along said curved path.

2. Apparatus as defined in claim 1, wherein said first conveyor and said lower run of said belt conveyor extend in substantially horizontal direction.

3. Apparatus as defined in claim 2, and including means for directing a stream of air in downward direction onto the particles freely dropping along said curved path.

4. Apparatus as defined in claim 1, wherein said upwardly moving run of said further belt conveyor is continued by a substantially horizontal extending portion having an end spaced from said magnet means so that the particles transported thereon are removed out of the magnetic field produced by said magnet means and drop in a stream downwardly from said end of said horizontally extending portion, and including means directing an airstream in substantially horizontal direction against the dropping particles so as to deflect any non-ferromagnetic material still clinging thereto out of the dropping stream of ferromagnetic particles.

5. Apparatus as defined in claim 4, and including receiver means for receiving the stream of dropping ferromagnet particles and guide means for guiding the deflected non-ferromagnetic particles away from said receiver means.

i i I! I t 

1. Apparatus for separating ferromagnetic particles from a mixture of said ferromagnetic particles and non-ferromagnetic particles comprising a first conveyor for transporting the mixture in a first direction; a belt conveyor having a lower run upwardly spaced from said first conveyor and extending in a direction transverse to said first direction with one end of said lower run transversely spaced from said first conveyor; a magnet arranged over said first conveyor spaced from said one end of said lower run and closely adjacent to that face of said lower run of said belt conveyor which faces away from said first conveyor so that the ferromagnetic particles and some of the nonferromagnetic particles clinging thereto will be lifted by said magnet onto said lower run and transported on the latter in said transverse direction out of the influence of the magnetic field of said magnet so that the lifted particles will fall freely along a curved path from said onE end of said lower run; a further belt conveyor having an upwardly moving run spaced from said magnetic field and said curved path; and magnet means located closely adjacent that face of said upwardly moving run which faces away from said curved path so that the ferromagnetic particles will be attracted by said magnet means while falling along said curved path and be deflected out of said curved path against said upwardly moving run to be transported by the latter and separated from the remaining non-ferromagnetic particles which will not be attracted but continue to drop along said curved path.
 2. Apparatus as defined in claim 1, wherein said first conveyor and said lower run of said belt conveyor extend in substantially horizontal direction.
 3. Apparatus as defined in claim 2, and including means for directing a stream of air in downward direction onto the particles freely dropping along said curved path.
 4. Apparatus as defined in claim 1, wherein said upwardly moving run of said further belt conveyor is continued by a substantially horizontal extending portion having an end spaced from said magnet means so that the particles transported thereon are removed out of the magnetic field produced by said magnet means and drop in a stream downwardly from said end of said horizontally extending portion, and including means directing an airstream in substantially horizontal direction against the dropping particles so as to deflect any non-ferromagnetic material still clinging thereto out of the dropping stream of ferromagnetic particles.
 5. Apparatus as defined in claim 4, and including receiver means for receiving the stream of dropping ferromagnet particles and guide means for guiding the deflected non-ferromagnetic particles away from said receiver means. 